Why in the news?

  • India’s first MWh-scale Vanadium redox flow battery was inaugurated by the Union Minister for Power.

Vanadium Flow Battery

  • What is it?: A Vanadium Flow Battery (VFB) is an electrochemical energy storage system where vanadium ions in liquid electrolytes store and release energy.
  • Working Principle:
    • Utilizes vanadium ions in four oxidation states (V²⁺, V³⁺, V⁴⁺, V⁵⁺) in two separate electrolyte tanks.
    • During charging, electrons move through an external circuit where ions change oxidation state and energy gets stored in the liquid.
    • During discharge, the reverse process releases energy.
    • The electrolytes circulate through a cell stack separated by an ion-exchange membrane.
  • Advantages:
    • Long cycle life (up to 20,000–25,000 cycles, 20+ years).
    • No cross-contamination since the same vanadium element is used in both tanks.
    • High safety: Non-flammable, no thermal runaway.
    • Scalability: Energy capacity depends on tank size
    • Deep discharge capability (up to 100% DoD).
    • Excellent for long-duration storage (4–10 hours).
  • Applications:
    • Grid-level renewable energy storage (solar/wind).
    • Peak shaving (Reducing consumption peak during periods of high demand) and load shifting (Moving the electricity consumption from peak time to off-peak hours).
    • Microgrids and remote power systems.
    • Backup power for industrial facilities.
    • Integration with green hydrogen and long-duration storage systems.
  • Limitations:
    • High upfront cost due to vanadium prices.
    • Lower energy density compared to lithium-ion.
    • Requires pumps and tanks, increasing space and maintenance needs.
    • Efficiency is lower than Li-ion battery- 70-80% as compared to the 90-95% efficiency of Li-ion.
  • Indian Context:
    • Interest rising due to energy transition and RE expansion (500 GW target by 2030).
    • India has significant vanadium deposits in Arunachal Pradesh, Odisha, and Karnataka.
    • MNRE promotes advanced battery technologies including flow batteries under R&D programs.
    • Used in pilot projects under Smart Grid Mission and Renewable Energy Storage missions.